Clinical testing of hearing sensitivity is usually performed by an audiologist using an audiometer that presents puretone stimuli at controlled frequencies and intensities. The test is performed by manually presenting stimuli according to loosely defined rules. Threshold, the lowest intensity of a stimulus that the listener can hear, is determined for each test frequency, also according to loosely defined rules. The method was first described in clinical publications, Hughson W, Westlake H: Manual for program outline for rehabilitation of aural casualties both military and civilians. Trans. Am. Acad. Ophthalmol. Otolaryngol. Suppl. 48, 1-15, 1944; Carhart R, Jerger J F: Preferred method for clinical determination of puretone thresholds. J.Speech Hear. Dis. 24:330-345, 1959, and later incorporated into a national standard. American National Standards Institute. American National Standard Methods for Manual Pure Tone Audiometry, ANSI S3,21-1978. However many aspects of the procedure are not standardized, such as the number of test stimuli, the temporal characteristics of the stimuli, and the rules for the use of contralateral masking noise.
Test results are influenced by a number of uncontrolled procedural and listener factors including the following.
The experience of the examiner
Shortcuts and methodologic biases of the examiner
Intraexaminer procedural variations
Interexaminer procedural variations
Previous experience of the listener
Listener response criterion
As a result of less than ideal methodologic control, the accuracy and test-retest reliability are compromised to an unknown extent. This limits the ability to compare test results across examiners and listeners as well as the ability to track changes in hearing sensitivity.
The present invention provides an Adaptive Method for Testing Auditory Sensitivity (AMTAS) wherein sensitivity of the auditory system is measured in a manner to reduce the problems associated with routine clinical hearing testing. The present invention, which may be used to replace clinical puretone audiometry in the diagnostic hearing evaluation, selects test ear and test frequency, provides contralateral masking when appropriate, and quantitatively assesses test reliability.